DESCRIPTION: An ultrasonic diagnostic apparatus has been proposed for Dental applications in determining tooth pathologies such as demineralization/caries, hidden fractures, and formation of abscesses. The equipment adopts a piezoelectric and laser optic hybrid transduction system for interrogation of teeth. Ultrasonic responses of the tooth structure will be analyzed by a pattern recognition expert system (artificial intelligence) to determine the diagnosis of the tooth inspected. The proposed research will eventually help to reduce the use of harmful X-ray radiation in Dental clinics and contribute to artificial intelligence based diagnosis. The proposed concept has been successfully demonstrated in the previous Phase I study. In this Phase II study, instrumentation for clinical data collection using a combination of conventional piezoelectric and new laser-based ultrasonic technologies will be developed and optimized; an artificial intelligence based diagnostic function will be developed using clinical data and implemented using embedded computing; numerical simulations will be used to enhance diagnostic function development; and finally, initial clinical trials will be conducted to demonstrate the performance of the prototype equipment. The ultrasonic apparatus for Dental diagnosis outlined in this application is a first application of AI-based NDE in Dentistry. The research concept may also extend to periodontal and craniofacial applications.